1. Field of the Invention
The invention relates to gas panels for supplying high purity process gas to a point-of-use location. More particularly, it relates to an improved gas panel having enhanced reliability and reduced potential of gas contamination.
2. Description of the Prior Art
In the semiconductor manufacturing industry and in various other industrial operations, gas cabinets are used to deliver high purity process gases to a point-of-use location, commonly referred to as a tool location. Such cabinets contain high purity gas supply cylinders and gas panels for delivering gases to the tool location.
For high purity gas operations, it is essential that the process gases be delivered to the tool location with minimum contamination since even parts-per-million impurity levels can adversely affect the efficiency of semiconductor and other high purity products. In addition, it is necessary to assure that the gas panels are capable of operating safely and without gas leakage that could jeopardize the health and safety of gas cabinet operators.
Gas panels are thus required to deliver gases at desired pressure levels while maintaining gas purity and maintaining safety integrity. The panels must also provide for purge functions to enable gas cylinder changes to be performed safely and without gas contamination. For such purposes, typical gas panels consist of specialized valves, components, interconnecting piping and associated hardware, with high purity, hazardous cylinders of gas being attached to the inlet to the gas panel, and the outlet thereof, attaching through a suitable pipeline to a process reactor.
A variety of gas panel arrangements have been proposed in the art to satisfy the various requirements for high purity process gas operations. In a representative gas panel, a flow limiting valve, an emergency shutoff valve, a gas regulator with high and low side gauges, and four manual valves are employed. A manual purge valve connects the nitrogen supply employed therein, and a manual process valve connects to the user system. Two vent valves connect the high and low side of the panel to vent means, including a vacuum generator module. The vacuum module contains an eductor driven by a nitrogen or other inert gas supply and exhausting to a vent stack system. A low side safety relief port connection to the vent stack is provided.
Despite such panel arrangements known in the art, there remains a genuine need for further gas panel improvements to meet the need for very high, or ultrahigh purity, gases to satisfy the ever increasing requirements of advanced process technologies for the semiconductor and other high technology industries. Such improvements must take into account that a large number of desired process gases are considered of a hazardous nature, i.e. are very toxic, corrosive, flammable or the like. The improvements desired in the art thus need to minimize contamination within the gas delivery panel and achieve enhanced control and handling of hazardous process gases.
It is an object of the invention, therefore, to provide an improved gas delivery panel.
It is another object of the invention to provide a gas panel capable of minimizing contamination of high purity process gases being delivered to a tool location.
It is a further object of the invention to provide an improved gas panel capable of enhancing the reliability and safety of high purity gas delivery operations.
With these and other objects in mind, the invention is hereinafter described in detail, the novel features thereof being particularly pointed out in the appended claims.